Dr Marc Davies

Dr Marc Davies

Senior Technician (Isotope Mass Spectrometry)

School of Geography, Earth and Environmental Sciences (Faculty of Science and Engineering)


My role is to manage, maintain and develop the isotope mass spectrometry facilities within the School of Geography, Earth and Environmental Sciences. This involves supporting research and teaching through technique development and the provision of analytical services for measuring the isotopic composition of a range of environmental samples and other materials. Currently, these facilities are housed in three specialist laboratories:

 The Stable Isotope Laboratory with two isotope ratio mass spectrometers and dedicated elemental analysers, gas preparation modules, and a GC with pyrolysis and combustion oven for compound specific analyses, together with a recirculating chemical work station and microbalance for sample preparation.

The Thermal Ionisation Mass Spectrometry Laboratory with a thermal ionisation mass spectrometer, and associated sample preparation facilities including two spot welders, a clean air loading station and a degasser.

The Sample Preparation Laboratory Suite comprises a small semi-clean laboratory with a HF rated fume cupboard, and larger general purpose laboratory with a fume cupboard used partly for reagent distillation, a clean air box and weighing station. Together, both laboratories are equipped for sample digestion, micro-distillation and column chemistry.


PhD Isotope Geochemistry, Open University (2008)
Thesis: The Origin and Petrogenesis of the Ethiopian Flood Basalts

PGCE (Geography), London University Institute of Education (1988)

MSc / DIC Mineral Exploration, Royal School of Mines, Imperial College, London (1986)

BSc (Hons) Geography &Geology (2:1), College of St. Paul and St. Mary, Cheltenham (1984)

Previous Positions

2013 – 2015 Project Officer (RESPIRE), Open University
Multi-proxy reconstruction of global oxygenation through the Cenozoic (56 – 25 Ma). Elemental, and Re-Os isotope analysis, and management and maintenance of NTIMS and associated clean labs

2012 – 2013 Research Technician (Stable Isotopes), Open University
Stable isotope analysis, and maintenance of ultra-clean laboratories and meteorite repository

2011 – 2012 Research Technician (GC/Stable isotopes/AAS), Open University
Analysis of peatland CH4 and NOx emissions using GC, 13C and 18O of foraminifera using IRMS, and biodegradability testing of composted waste using bespoke laboratory methods, AAS and GC

2009 – 2011 PETM Research Technician (NTIMS Manager), Open University
Elemental, and Re-Os and Sr isotope analysis, and management and maintenance of NTIMS and associated clean labs

2007 – 2008 Research Technician (U-Series), Open University
Sample preparation and analysis of uranium isotopes in carbonates using MC-ICPMS

2006 – 2007 Research Technician (Re-Os isotopes), Open University
Elemental, and Re-Os isotope analysis of sediments across the Permo-Triassic Boundary in China

1994 – 2000 Science Co-ordinator, Stourbridge College
Departmental manager for Science, and lecturer in geography and environmental science

1993 – 1994 Lecturer in Geography and Environmental Studies, South Bristol College
Lecturer in environmental issues, housing and urban development (Access)

1991 – 1994 Subject Leader (Geography and Environmental Studies), Soundwell College, Bristol
Lecturer in geography and environmental studies, and manager of related courses

1990 – 1991 Research Technician (Fission Track Analysis), La Trobe/Melbourne University, Australia
Operation, maintenance and development of mineral separation facilities for fission track analysis

1989 – 1990 Research Technician (Fission Track Analysis), University College London
Operation, maintenance and development of mineral separation facilities for fission track analysis

1988 – 1989 Assistant Scientific Officer (Geochemistry), British Geological Survey
Analysis of marine sediments for elemental contents using Arc-OES and Hg and Sb using AAS, and mapping of trace-metal concentrations to identify gold and silver mineralization.

1987 – 1988 Assistant Scientific Officer (Geochemistry), British Geological Survey
Collection, preparation and multi-element analysis of soils, stream sediments and natural waters using titration, fluorimetry, Arc-OES and AAS - compiled in a Geochemical Atlas of the British Isles.

1986 Project Assistant (Lorry Management) Environmental Resources Ltd, London
Preparation of reports and statistical summaries of environmental survey data

Teaching interests

2015 – Pres. Current teaching includes the supervision of MGEOL project work, and training of post graduate and post-doctoral researchers in laboratory techniques and isotopic analysis

2010 Associate Lecturer (Geology), Understanding the Continents (S339), Open University

2003, 04, 07, 08, 10 Senior Tutor (Geology), Mountain Building in Scotland (SXR339), Open University

2001, 02, 09, 11 Senior Tutor (Geology), The Geological History of the British Isles (SXR260), Open University

1994 – 2000 Lecturer in Geography and Environmental Science, A level, IB, Access, GNVQ and BSc foundation), Stourbridge College

1993 – 1994 Lecturer in Environmental Issues, Housing and Urban Development, Access, South Bristol College

1991 – 1994 Lecturer in Geography, Urban Development and Environmental Studies, A level, Access and GCSE), Soundwell College, Bristol

Research interests

My principal research interest is in developing analytical techniques that can be used to explain processes at work in the natural world. In particular, I am intrigued by how chemical signatures in mantle-derived rocks can help us understand what’s going on inside the Earth. To this end my PhD focused on the role of mantle plumes in continental breakup and the formation of large igneous provinces, and the possibility that mantle plumes may be sourced at the core-mantle boundary. I used rhenium-osmium and noble gas isotopes alongside major and trace element analyses to constrain the source and petrogenesis of the Ethiopian flood basalts, which represent the earliest outpourings of Afro-Arabian Large Igneous Province. Further exploration of the relationship between large igneous provinces and environmental change has inspired a shift in the focus of my analysis to the sedimentary record in search of comparable chemical signatures which might clarify the mechanisms that contribute such change. I have since been involved in generating high resolution isotopic data for successions of organic-rich mudrocks and carbonates (including foraminifera, bivalve shells and calcareous sediments) to highlight variations in ocean chemistry that reflect paleoclimatic change coincident with the eruption of large igneous provinces. For this work I have used a range of analytical instruments including XRF, OES and ICPMS for major and trace element concentrations, MC-ICPMS for Re, Mo and U isotopes, TIMS for Os and Sr isotopes, and IRMS for C and O isotopes. For the future, I am keen to develop novel ways of using our recently acquired suite of high precision stable isotope instrumentation here at Plymouth, and to explore collaborations that might benefit from such developments.

Key publications are highlighted


Percival, L.M.E., Cohen, A.S., Davies, M.K., Dickson, A.J, Hesselbo, S.P., Jenkyns, H.C., Leng, M.J., Mather, T.A., Storm, M.S., Xu, W. (2016), Osmium isotope evidence for two pulses of increased continental weathering linked to Early Jurassic volcanism and climate change, Geology, Vol. 44; no. 9; p. 759–762

Dickson, A.J., Cohen, A.S., Coe, A.L., Davies, M., Shcherbinina, E. and Gavrilov, Y. (2015), Evidence for weathering and volcanism during the PETM from Arctic Ocean and Peri-Tethys osmium isotope records, Palaeogeography, Palaeoclimatology, Palaeoecology 438,300-307.

Rogers, N.W., Davies M.K., Parkinson I.J., Yirgu G. (2010), Osmium isotopes and Fe/Mn ratios in Ti-rich picritic basalts from the Ethiopian flood basalt province: No evidence for core contribution to the Afar plume, Earth and Planetary Science Letters 296 413–422

Davies, M. (2004), A curate’s egg: beyond the plume hypothesis – a student’s eye view of the Penrose Conference,Geoscientist, Vol. 14, No. 1 (Jan. 2004) - also published in West Australian Geologist, No. 437, April (2004)


Dickson, A.J, Cohen, A.S and Davies, M.K (In Press), The osmium isotope signature of Phanerozoic Large Igneous Provinces, In ‘Environmental change and large igneous provinces: the deadly kiss of LIPs’ Ed. Ernst, R, AGU Books

Conference Papers

Davies, M.K., Cohen, A.S., Dickson, A.J., Bagard, M.-L., Osmium-isotope insights into Arctic Ocean hydrography during Early Eocene greenhouse warming, Discussion Meeting, ’Hyperthermals: rapid and extreme global warming in our geological past’, The Royal Society, September (2017)

Bagard, M.-L., Dickson, A.J., Davies, M.K., Cohen, A.S., Global ocean oxygenation during the ETM-2: Clues from uranium isotopes, Discussion Meeting, ’Hyperthermals: rapid and extreme global warming in our geological past’, The Royal Society, September (2017)

Bagard, M-L., Dickson, A., Davies, M. and Cohen, A., Global Seawater Oxygenation during the Eocene: New Constraints from Molybdenum and Uranium Isotopes, 26th Goldschmidt Conference, Yokohama, June (2016)

Percival, L., Cohen, A., Davies, M., Dickson, A., Jenkyns, H., Hesselbo, S., Mather, T., Xu, W., Storm, M., Osmium isotope perturbations during the Pliensbachian–Toarcian (Early Jurassic): Relationships between volcanism, weathering, and climate change, Geophysical Research Abstracts, Vol. 18, EGU2016-13046, 2016, EGU General Assembly (2016)

Stuart, F., Rogers, N. and Davies, M., The He isotope composition of the earliest picrites erupted by the Ethiopia plume, implications for mantle plume source, Geophysical Research Abstracts, Vol. 18, EGU2016-17009, EGU General Assembly (2016)

Bagard, M.-L., Dickson, A. J., Davies, M. K. and Cohen, A. S., Evaluating δ238/235U records in mudrocks as a proxy for ocean oxygenation during the Early Eocene, Goldschmidt Abstracts, 2015, article no. 172 (2015)

Bagard, M-L., Davies, M., Dickson, A. J. and Cohen, A.S., Multi proxy reconstruction (δ98/95Mo, δ238/235U) of global ocean oxygenation during the Early Eocene, AGU Fall Meeting , December 2014, San Francisco, CA, USA (2014)

Stuart, F. M. Rogers, N., Parkinson, I. Davies, M., Constraints on the source of mantle plumes from the geochemistry of the first picrites erupted, Ethiopian flood basalt province, EGU General Assembly, Vienna, Austria, April (2012)

Fehr, M., Izon, G., Dickson, A., Davies, M., Cohen, A., Rhenium concentration and isotopic analysis by MC-ICPMS, European Winter Conference on Plasma Spectrochemistry, Zaragoza February (2011)

Cohen, A.S. Saunders, A., Zhang, H. Li, J. Davies, M.K., Variations in Os- and Mo-isotope compositions and trace element abundances across the Permo-Triassic boundary, Meishan, China:Proxy evidence for large-scale oceanic anoxia? American Geophysical Union, Fall Meeting (2009)

Parkinson, I.J., Rogers, N.W., Davies, M.K. and Yirgu, G., Mantle Plumes: ambiguous messengers from the deep mantle, William Smith Meeting, The Deep Earth: The structure and evolution of the interior of our planet, Geological Society of London, November (2005)

Davies, M., Parkinson, I.J. and Rogers, N.W., The origin of high-Ti picrites from the Ethiopian flood basalt province, Penrose Conference - Plume IV: Beyond the Plume Hypothesis, Hveragerdi, Iceland, GSA, August (2003)

Davies, M., Parkinson, I.J. and Rogers, N.W., The origin of high-Ti picrites from the Ethiopian flood basalt province, Mantle plumes: Physical processes, chemical signatures, biological effects, National Museum of Wales, Cardiff, September (2003)

Davies, M., Parkinson, I.J. and Rogers, N.W., Does the core contribute to deep mantle sourced plumes? EGS-AGU-EUG Joint Assembly, Nice, France, April (2003)

Rogers, N.W., Davies, M., Parkinson, I.J. and Yirgu, G., Contrasting geochemistry of basalts from the Afar and East African mantle plumes, EGS-AGU-EUG Joint Assembly, Nice, France, April (2003)

Davies, M., Rogers, N.W. and Parkinson, I.J., High-Ti picrites from the Ethiopian Plateau, Volcanic and Magmatic Studies Group Annual Meeting (Part II), University of Edinburgh, December (2002)

Davies, M., Parkinson, I.J. and Rogers, N.W., Picrites and ferro-picrites from the Ethiopian Plateau: possible origin at the core mantle boundary, Volcanic and Magmatic Studies Group Annual, University College London, January (2002)